Locks layout panel.

<div class="definition">
    lock(panel, message, [showSpinner])
</div>

<div class="arguments">
    <table>
    <tr>
        <td>message</td>
        <td><b>string</b>, message</td>
    </tr>
    <tr>
        <td>showSpinner</td>
        <td><b>boolean</b>, <i>optional</i>, spinner indicator</td>
    </tr>
    </table>
</div>

<h4>Description</h4>

This method will lock the panel by added a semi-transparent div on top of popup content. The user will not be able to interact with
the panel or its content until the panel is unlocked with <a href="w2layout.unlock" class="method">.unlock()</a>. This method will call
<a href="w2utils.lock" class="method">w2utils.lock()</a> to perform the locking.
The first argument <span class="argument">type</span> is the name of the panel. It can be one of the following:
<ul style="margin-left: 50px">
    <li>top
    <li>left
    <li>main
    <li>right
    <li>preview
    <li>bottom
</ul>
You have 3 options how you want to lock the content. Lock with a message and a spinner:
<textarea class="javascript">
w2layout.lock('main', 'Loading...', true);
</textarea>

Lock w/o a message, but with a spinner:
<textarea class="javascript">
w2layout.lock('main', '', true);
</textarea>

Lock w/o a message and w/o a spinner:
<textarea class="javascript">
w2ui.layout.lock('main');
</textarea>